Irish police say they are confident they will arrest the dissident republicans responsible for firing shots at the funeral of Real IRAterror boss Alan Ryan over the weekend.

The 32-year-old was shot dead in Clongriffin in North Dublin in broad daylight last week. The head of a Dublin faction of the Real IRA, it is understood a crime gang ordered a hit on his life.

In 2000, Ryan had been jailed over the discovery of a Real IRA training camp in County Meath.

A large number of dissident republicans travelled from Derry and Belfastfor the funeral. Detectives from the Special Branch took a record of those who arrived at the Ryan home in Donaghmede on Saturday morning.

Several men dressed in military-style uniforms fired three shots into the air as the coffin of Ryan was removed from the family home shortly after 9am.

After the incident took place, police decided not to intervene, amid fears arrests would lead to a "full-scale riot situation." Instead they kept those responsible under surveillance. The Irish Independent reports an investigative headquarters was established in Clontarf where both Irish and PSNIofficers are liaising.

In a statement, Mr Shatter said, "I recognize fully the immediate difficulties which face An Garda Síochána when people take advantage of a funeral to behave in this fashion.

"But the Garda commissioner has assured me that they are pursuing rigorously any breaches of the law which took place.

"The gardai, together with their colleagues in Northern Ireland, will continue to take every action open to them to deal with the activities of members of these groups, whether they are engaging in terrorism or organised crime."